Portable printing system



FIG. 1 is a perspective view of a portable printing system showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a right side elevation thereof;

FIG. 5 is a left side elevation thereof;

FIG. 6 is a left end perspective view thereof; and,

FIG. 7 is a right end perspective view thereof. 

The ornamental design for a portable printing system, as shown and described. 